Mike Thomp­son, who with his brother David runs a cray-fish­ing em­pire worth $200 mil­lion, wants re­search into the ef­fects of soar­ing oc­to­pus num­bers af­ter claims they are cost­ing the in­dus­try up to $10 mil­lion a year.

A re­cent study by the Univer­sity of Ade­laide found oc­to­puses had thrived in the world’s oceans over the past 60 years as wa­ters warmed and com­pet­ing species were over­fished.

Mr Thomp­son agreed with the find­ings, say­ing in his 40-year ca­reer at sea he had never seen as many of the mol­luscs as he had re­cently.

What was more, he said, the soar­ing num­bers of the an­i­mals were a direct threat to the west­ern rock lob­ster fishery, WA’s most valu­able, with an­nual sales of $400 mil­lion.

Oc­to­puses are a nat­u­ral preda­tor of cray­fish and are able to at­tack them by in­fil­trat­ing the pots com­monly used by com­mer­cial fish­ers off the WA coast.

Mr Thomp­son said the losses were be­ing com­pounded by the dam­age the lob­sters in­flicted on them­selves as they tried to fight off the preda­tors.

West­ern Rock Lob­ster Coun­cil chief ex­ec­u­tive John McMath said oc­to­puses had al­ways been a “reg­u­lar en­counter” for lob­ster fish­er­men but “I haven’t heard of them be­ing a ma­jor prob­lem”.

Mr McMath was also cau­tious about over­haul­ing the de­sign of lob­ster pots.

“The na­ture of a cray­pot means you’re go­ing to have gaps, and I don’t know whether you’ve ever seen an oc­cie in there but they’re slip­pery suck­ers and they can get into al­most any­thing,” he said.

They’re slip­pery suck­ers and they can get into al­most any­thing. John McMath